This seems to be a fairly consistent problem for new users.

 The create-or-move is adjusting the crush weight, not the osd weight.
Perhaps the init script should set the defaultweight to 0.01 if it's <= 0?

It seems like there's a downside to this, but I don't see it.




On Fri, Mar 20, 2015 at 1:25 PM, Robert LeBlanc <[email protected]>
wrote:

> The weight can be based on anything, size, speed, capability, some random
> value, etc. The important thing is that it makes sense to you and that you
> are consistent.
>
> Ceph by default (ceph-disk and I believe ceph-deploy) take the approach of
> using size. So if you use a different weighting scheme, you should manually
> add the OSDs, or "clean up" after using ceph-disk/ceph-deploy. Size works
> well for most people, unless the disks are less than 10 GB so most people
> don't bother messing with it.
>
> On Fri, Mar 20, 2015 at 12:06 PM, Bogdan SOLGA <[email protected]>
> wrote:
>
>> Thank you for the clarifications, Sahana!
>>
>> I haven't got to that part, yet, so these details were (yet) unknown to
>> me. Perhaps some information on the PGs weight should be provided in the
>> 'quick deployment' page, as this issue might be encountered in the future
>> by other users, as well.
>>
>> Kind regards,
>> Bogdan
>>
>>
>> On Fri, Mar 20, 2015 at 12:05 PM, Sahana <[email protected]> wrote:
>>
>>> Hi Bogdan,
>>>
>>>  Here is the link for hardware recccomendations :
>>> http://ceph.com/docs/master/start/hardware-recommendations/#hard-disk-drives.
>>> As per this link, minimum  size  reccommended for osds  is 1TB.
>>>  Butt as Nick said, Ceph OSDs must be min. 10GB to get an weight of
>>> 0.01
>>> Here is the snippet from crushmaps section of ceph docs:
>>>
>>> Weighting Bucket Items
>>>
>>> Ceph expresses bucket weights as doubles, which allows for fine
>>> weighting. A weight is the relative difference between device capacities.
>>> We recommend using 1.00 as the relative weight for a 1TB storage
>>> device. In such a scenario, a weight of 0.5 would represent
>>> approximately 500GB, and a weight of 3.00 would represent approximately
>>> 3TB. Higher level buckets have a weight that is the sum total of the leaf
>>> items aggregated by the bucket.
>>>
>>> Thanks
>>>
>>> Sahana
>>>
>>> On Fri, Mar 20, 2015 at 2:08 PM, Bogdan SOLGA <[email protected]>
>>> wrote:
>>>
>>>> Thank you for your suggestion, Nick! I have re-weighted the OSDs and
>>>> the status has changed to '256 active+clean'.
>>>>
>>>> Is this information clearly stated in the documentation, and I have
>>>> missed it? In case it isn't - I think it would be recommended to add it, as
>>>> the issue might be encountered by other users, as well.
>>>>
>>>> Kind regards,
>>>> Bogdan
>>>>
>>>>
>>>> On Fri, Mar 20, 2015 at 10:33 AM, Nick Fisk <[email protected]> wrote:
>>>>
>>>>> I see the Problem, as your OSD's are only 8GB they have a zero weight,
>>>>> I think the minimum size you can get away with is 10GB in Ceph as the size
>>>>> is measured in TB and only has 2 decimal places.
>>>>>
>>>>> For a work around try running :-
>>>>>
>>>>> ceph osd crush reweight osd.X 1
>>>>>
>>>>> for each osd, this will reweight the OSD's. Assuming this is a test
>>>>> cluster and you won't be adding any larger OSD's in the future this
>>>>> shouldn't cause any problems.
>>>>>
>>>>> >
>>>>> > admin@cp-admin:~/safedrive$ ceph osd tree
>>>>> > # id    weight    type name    up/down    reweight
>>>>> > -1    0    root default
>>>>> > -2    0        host osd-001
>>>>> > 0    0            osd.0    up    1
>>>>> > 1    0            osd.1    up    1
>>>>> > -3    0        host osd-002
>>>>> > 2    0            osd.2    up    1
>>>>> > 3    0            osd.3    up    1
>>>>> > -4    0        host osd-003
>>>>> > 4    0            osd.4    up    1
>>>>> > 5    0            osd.5    up    1
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
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>>>>
>>>>
>>>
>>
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